The Catacombs
Through all iterations of life and death on the island, the Kastari built several catacombs to accommodate the dead. Once they were full their entrance was shut and hidden, providing the dead with the peace they deserved. Throughout the years the landscape has changed and the landmarks for these catacombs has disappeared. Sealed for an eternity of peace and calm deep below the surface.
Or at least, so they thought.
Dark forces had began to slip out of Ethna. Inhabitants on the island would start waking up in the middle of the night to the sounds of a deep, muffled chanting in a language unknown to them. Most of the reports of these sounds were discarded as nightmares, but the ones who had heard them knew something terrible was in the making.
The Kastari's once buried, was starting to come back from their graves.